This invention relates generally to food thawing and more particularly to a simple, inexpensive device to quickly and sanitarily thaw frozen food in a restaurant or institutional food setting.
Food is commonly frozen both for transportation and to prolong the effective life of the food between the time it is harvested or processed and the time it is served. Meat in particular is subject to spoilage or to infection with dangerous bacteria Moreover, meat, because of its density and weight, thaws slowly compared to most other food products that might be frozen, like vegetables. Moreover, meat can rarely be cooked directly from the frozen state, but must be thawed first before cooking. Furthermore, meat is an expensive food and may form a substantial part of the cost of ingredients for a meal in a restaurant or an institutional setting. Moreover, meat can toughen, dry out or lose the quality if it is thawed improperly or too quickly.
Institutional food service or restaurants can plan ahead by thawing expected amounts of meat before the meat is required to be cooked. However, meat quickly spoils, especially if thawed at high temperatures. If too much meat is thawed, the meat can spoil , hence can be costly to a restaurant operator or institutional food operator. On the other hand, if an insufficient amount of meat is thawed to meet the demands, a restaurant may run out of the ingredients for a particular dish and lose the opportunity to serve that dish that evening, hence the profits that would be associated with service of that particularly popular dish. Consequently, in a restaurant or institutional food service setting there is a need to balance the need for quickly thawing food versus the impairment in the quality of the food that can be caused by a quick thawing process while keeping in mind the possibility of spoilage or bacterial infestation in the food and the need to meet health department requirements and to protect one""s customers from infection. Consequently, there is no single satisfactory method for thawing food, although a variety of methods are employed.
One common method is to simply allow the meat to thaw in open air. However, this takes a substantial amount of time and is certainly one of the slowest way of thawing food. For a large piece of meat this may take twelve to fourteen hours. Moreover, it is possible the exposure to air during the period of time may cause the meat to become dried out. If the meat is left exposed too long to air, it may reach a temperature conducive to bacteria growth, hence lead to spoilage or infection.
The thawing process may b e accelerated by exposing the meat to forms of energy such as microwaves or heated air. This will accelerate the process of thawing, but can cook portions of the meat unless very carefully monitored. It is very difficult to maintain a constant temperature throughout a piece of meat because meat does not readily conduct heat, hence the outside portions of a cut of meat that is more exposed to the ambient energy, he it heated air or microwaves, may begin to cook before the inside portion of the meat is fully thawed. This is an undesirable result and may also facilitate bacteria growth in the meat being thawed in this fashion.
Another way of thawing meat is to put the meat in a sink filled with water. While this shortens the thawing time of the process, the water, unless recirculated, does not thaw the meat as fast as possible because the meat is not exposed to a constant water temperature because as the water chills around the meat, the temperature gradient between the meat surface and the water surface approaches stabilization and there is less thawing effect in the stagnant water. Moreover, even carefully packaged food may leak juices into the outside water or the outside water may seep into the packaged food. This is undesirable from a health standpoint if the sink is to be used for other things, unless the sink is carefully cleaned and disinfected. Moreover, this method ties a sink up for hours during the thawing process. One may choose to place the frozen item, especially meat, in a sink and run water over it. This means there is a constant flow of water at a constant temperature over the product that is to be thawed. However, there is no guarantee there will be complete coverage of the surface of the product as is the case when the product is completely submerged within a reservoir of liquid. Also, running water means at some point the water must overflow into a drain, resulting in a constant wastage of water at the flow rate of the water. The defrosting will operate most efficiently with a high flow rate which also guarantees a high wastage of the water involved. Using running water does not solve the problem of potential contamination of the sink by escaped juices from the meat product, nor does it solve the problem of using a sink during the period of time the meat is being thawed.
Consequently, a variety of devices that have been proposed that use a stand apart reservoir and recirculate water to thaw meat. Halterman et al. U.S. Pat. No. 5,797,270 proposes using a refrigerator chill device to thaw frozen food. Here there is a sealable chamber that circulates water chilled by coils to a temperature of 38 to 40 degrees. This device uses a refrigeration unit built into a housing, water is circulated through a circulation chamber and by the refrigeration unit to more quickly thaw food suspended is the circulation chamber. Fuller et al. U.S. Pat. No. 5,665,412 uses a sink-like device with a connected drain and faucet. Water is forcibly circulated through the sink-like water reservoir. When the circulated water reaches a certain level, it flows into a trough which collects any food particles, juices or debris that have broken loose from the food by the water circulation. There are other approaches such as using sound energy with a frequency spectrum matching the relaxation frequency spectrum of ice crystals as shown in Kissam, U.S. Pat. No. 4,504,498. Powers, U.S. Pat. No. 4,062,277 uses a spray field with sprayed water to pass over meat held in racks above a collection drain which recirculates the sprayed water. However, despite all this work no fully satisfactory method has been devised. Most restaurants thaw frozen food by exposing the food to an environment with a higher air temperature than freezing or by placing it in a sink and running water over it with the consequent water wastage and expense.
The present invention utilizes at least one water container that may be made like an off-the-shelf plastic bucket as a reservoir for water. At least one second container is used as a basket for suspending food in the reservoir of water in the first container. A pump is used to recirculated the water through both containers and to assure full and even exposure of the food product being thawed to the water held within the reservoir. This device avoids water wastage caused by running water in a sink, while assuring water circulation. The device is easily cleaned because the containers are easily washed by hand or by a mechanical dishwasher. This device reduces bacteria growth by maintaining a constant cooler thawing temperature as the food is thawed. This method is faster exposure to the ambient temperature in the environment and wastes less water, hence money, than running water over the food in a sink. These and other advantages of the current invention will be made more clear in the following description of a best mode for practicing the invention.